This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
High Speed Packet Access (HSPA) is a protocol used within Wideband Code Division Multiple Access (WCDMA) and it comprises two mobile telephony protocols: High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA). HSPDA and HSUPA extend and improve the performance of existing WCDMA protocols by improving the capacity and throughput while reducing latency. In particular, HSUPA provides fast uplink packet switch data services in the uplink direction with a shorter Transmission Time Interval (TTI) and Hybrid ARQ (HARM) with incremental redundancy, which makes retransmissions more effective. In HSUPA, the Enhanced Dedicated Physical Data Channel (E-DPDCH) and the Enhanced Dedicated Physical Control Channel (E-DPCCH) are provided to carry the uplink packet data and the associated control information, respectively.
HSUPA also uses a packet scheduler that operates on a request-grant basis, where at any given time, a number of User Equipments (UEs) may request a permission to send data in the uplink direction. In response, the HSUPA scheduler allocates radio resources on the uplink to the requesting UEs by keeping a tight control on the total received power (or equivalently, Rise-over-Thermal (RoT)). The amount of data that a UE can transmit depends on the transmit power grant allocated to that UE by the HSUPA scheduler. The higher the grant, the more data a UE can transmit.